Electronic Structure and Chemical Bond of Titanium Diboride

1　IntroductionTitaniumdiboride (TiB2 )hasattractedmuchatten tionrecentlybecauseofitshighmeltingpoint,hardnessandchemicalstability .Ontheotherhand ,TiB2 hasfineelectricalproperty ,soitmaybeusedinwide rangingfields1-3 ] .Aswellknown ,thepropertiesofmaterialsaredecidedbythestructures .Obviously ,thespecialpropertyofTiB2 isrelatedtoitsstructuresofcrystalandelectrons .However ,thereislessstudyonstructuresofvalenceelec tronsandtypeofchemicalbondofTiB2 .JiJia mingetal4] studiedtheelectronicst…

Electronic structure and chemical bond of titanium diboride

Titanium diboride was calculated by the density function and discrete variational (DFT-DVM) method to study the relation between structure and properties. Titanium and its first-nearest boron atoms form a strong covalent bond, so TiB₂ has high melting point, hardness and chemical stability. Titanium atom releases two electrons to form Ti²⁺ ions, and a boron atom gets one electron to come into B⁻ ion. B⁻ takes the sp² hybrid and forms σ bonds to link other boron atoms in the same layer. The other one 2p_z orbital of every B⁻ ion in the same layer interacts each other to form the π molecular orbital, so TiB₂ has fine electrical property. The calculated density of state is close to the result of XPS experiment of TiB₂. Mainly Ti3d and B2p atomic orbitals contribute the total DOS near the Fermi level. MIN Xin-min: Born in 1953 Funded by the National Natural Science Foundation of China (No. 59802008)